A vehicle air-conditioning system includes a plurality of sensors for conditioning air such as a vehicle interior temperature sensor which detects a temperature of a vehicle interior, a vehicle exterior temperature sensor which detects a temperature of a vehicle exterior (external air) and a solar radiation sensor which detects the amount of solar radiation entering a vehicle. The vehicle air-conditioning system is configured to calculate a target temperature, the blast volume or the like from the output of these sensors and a temperature value set by an operator (passenger), so as to blow out conditioned air inside a vehicle from a predetermined outlet (for example, refer to Patent Document 1).
By taking the amount of solar radiation entering a vehicle, which is detected by the solar radiation sensor, into consideration in the air-conditioning of the air-conditioning system as described above, more comfortable air-conditioning can be provided for a passenger in a vehicle.